You also can consider writing your SP this way:

CREATE PROC KRCityContacts

@city varchar(20) = NULL,

@OUTMSG VARCHAR(100) OUTPUT

AS

SET @OUTMSG = ''

IF @city IS NOT NULL

BEGIN

SELECT CompanyName

FROM Customer

WHERE CompanyName IS NOT NULL

AND City...

Hi! Try this to call it. Then you can use @rc or not.

DECLARE @CITY VARCHAR(20), @rc INT

EXEC KRCityContacts 'Asheville', @rc

SELECT @rc